diff --git a/java/google/registry/tools/CurlCommand.java b/java/google/registry/tools/CurlCommand.java
index 3804b8d48..9e0e744e5 100644
--- a/java/google/registry/tools/CurlCommand.java
+++ b/java/google/registry/tools/CurlCommand.java
@@ -14,11 +14,15 @@
 
 package google.registry.tools;
 
+import static com.google.common.base.Preconditions.checkArgument;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
+import com.beust.jcommander.IStringConverter;
 import com.beust.jcommander.Parameter;
 import com.beust.jcommander.Parameters;
+import com.beust.jcommander.converters.IParameterSplitter;
 import com.google.common.base.Joiner;
+import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.net.MediaType;
@@ -50,6 +54,7 @@ class CurlCommand implements CommandWithConnection {
 
   @Parameter(
       names = {"-t", "--content-type"},
+      converter = MediaTypeConverter.class,
       description =
           "Media type of the request body (for a POST request.  Must be combined with --body)")
   private MediaType mimeType = MediaType.PLAIN_TEXT_UTF_8;
@@ -58,6 +63,7 @@ class CurlCommand implements CommandWithConnection {
   // GET...)
   @Parameter(
       names = {"-d", "--data"},
+      splitter = NoSplittingSplitter.class,
       description =
           "Body for a post request.  If specified, a POST request is sent.  If "
               + "absent, a GET request is sent.")
@@ -95,4 +101,20 @@ class CurlCommand implements CommandWithConnection {
                 Joiner.on("&").join(data).getBytes(UTF_8));
     System.out.println(response);
   }
+
+  public static class MediaTypeConverter implements IStringConverter<MediaType> {
+    @Override
+    public MediaType convert(String mediaType) {
+      List<String> parts = Splitter.on('/').splitToList(mediaType);
+      checkArgument(parts.size() == 2, "invalid MediaType '%s'", mediaType);
+      return MediaType.create(parts.get(0), parts.get(1)).withCharset(UTF_8);
+    }
+  }
+
+  public static class NoSplittingSplitter implements IParameterSplitter {
+    @Override
+    public List<String> split(String value) {
+      return ImmutableList.of(value);
+    }
+  }
 }
diff --git a/javatests/google/registry/tools/CurlCommandTest.java b/javatests/google/registry/tools/CurlCommandTest.java
index 84144524d..4275620c1 100644
--- a/javatests/google/registry/tools/CurlCommandTest.java
+++ b/javatests/google/registry/tools/CurlCommandTest.java
@@ -79,6 +79,37 @@ public class CurlCommandTest extends CommandTestCase<CurlCommand> {
             eq("some data".getBytes(UTF_8)));
   }
 
+  @Test
+  public void testPostInvocation_withContentType() throws Exception {
+    runCommand(
+        "--path=/foo/bar?a=1&b=2",
+        "--data=some data",
+        "--service=DEFAULT",
+        "--content-type=application/json");
+    verify(connection).withService(DEFAULT);
+    verifyNoMoreInteractions(connection);
+    verify(connectionForService)
+        .sendPostRequest(
+            eq("/foo/bar?a=1&b=2"),
+            eq(ImmutableMap.<String, String>of()),
+            eq(MediaType.JSON_UTF_8),
+            eq("some data".getBytes(UTF_8)));
+  }
+
+  @Test
+  public void testPostInvocation_badContentType() throws Exception {
+    assertThrows(
+        IllegalArgumentException.class,
+        () ->
+            runCommand(
+                "--path=/foo/bar?a=1&b=2",
+                "--data=some data",
+                "--service=DEFAULT",
+                "--content-type=bad"));
+    verifyNoMoreInteractions(connection);
+    verifyNoMoreInteractions(connectionForService);
+  }
+
   @Test
   public void testMultiDataPost() throws Exception {
     runCommand(
@@ -93,6 +124,20 @@ public class CurlCommandTest extends CommandTestCase<CurlCommand> {
             eq("first=100&second=200".getBytes(UTF_8)));
   }
 
+  @Test
+  public void testDataDoesntSplit() throws Exception {
+    runCommand(
+        "--path=/foo/bar?a=1&b=2", "--data=one,two", "--service=PUBAPI");
+    verify(connection).withService(PUBAPI);
+    verifyNoMoreInteractions(connection);
+    verify(connectionForService)
+        .sendPostRequest(
+            eq("/foo/bar?a=1&b=2"),
+            eq(ImmutableMap.<String, String>of()),
+            eq(MediaType.PLAIN_TEXT_UTF_8),
+            eq("one,two".getBytes(UTF_8)));
+  }
+
   @Test
   public void testExplicitPostInvocation() throws Exception {
     runCommand("--path=/foo/bar?a=1&b=2", "--request=POST", "--service=TOOLS");